Entomology : with special reference to its biological and economic aspects . con-spicuous —The physiology of the fat-system is still ob-scure. Probably the fat-body combines several functions. Incaterpillars and other larvre it furnishes a reserve supply ofnutriment, at the expense of which the metamorphosis takesplace; the amount of fat increases as the larva grows, anddiminishes in the pupal stage, though some of it lasts over tofurnish nourishment for the imago and its germ cells. Thegradual accumulation of uric acid and urates in the fat- ^^^- ^*^5- body indicates an
Entomology : with special reference to its biological and economic aspects . con-spicuous —The physiology of the fat-system is still ob-scure. Probably the fat-body combines several functions. Incaterpillars and other larvre it furnishes a reserve supply ofnutriment, at the expense of which the metamorphosis takesplace; the amount of fat increases as the larva grows, anddiminishes in the pupal stage, though some of it lasts over tofurnish nourishment for the imago and its germ cells. Thegradual accumulation of uric acid and urates in the fat- ^^^- ^*^5- body indicates an excretoryfunction, particularly in Col-lembola, which have no Mal-pighian tubes. The intimateassociation between the ulti-mate tracheal branches andthe fat-body has led someauthorities to ascribe a res-piratory function to the lat-ter. A close relation ofsome sort exists also be-tween the fat-system andthe blood-system; fat-cellsare found free in the blood, and the blood corpuscles originate in the thorax and abdo-men from tissues that can scarcely be distinguished from. Section through fat-body of a silkworm,showing nucleated cells, loaded with dropsof fat. ANATOMY AND PHYSIOLOGY 131 Fig. 166,
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectentomology, bookyear1
